# -*- coding: utf-8 -*-
# Define here the models for your spider middleware
#
# See documentation in:
# https://doc.scrapy.org/en/latest/topics/spider-middleware.html

from scrapy import signals
import time
from scrapy.http import HtmlResponse
from zhihu.utils.proxy_ip import GetIP


# class RandomProxyMiddleware(object):
#     """设置动态ip"""
#     def process_request(self, request, spider):
#         get_ip = GetIP()
#         request.meta["proxy"] = get_ip.get_random_ip()


class ZhihuMiddleware(object):

    def process_request(self, request, spider):
        """
        重写Middleware中间件
        使用selenium模拟登录
        :param request:
        :param spider:
        :return:
        """
        if spider.name == 'pazhihu':
            # 调用browser发送请求
            spider.browser.get(request.url)
            # 通过xpath定位元素
            spider.browser.find_element_by_xpath('//span[@data-reactid="94"]').click()
            # 通过name定位元素
            spider.browser.find_element_by_name('username').send_keys('17601009336')
            time.sleep(3)
            # 通过name定位元素
            spider.browser.find_element_by_name('password').send_keys('123456liu')
            time.sleep(2)
            # 通过xpath定位元素
            spider.browser.find_element_by_xpath('//button[@type="submit"]').click()
            time.sleep(3)
            js = "var q=document.documentElement.scrollTop=200"
            spider.browser.execute_script(js)
            time.sleep(30)

            # 不用返回给下载器，直接返回给spider
            return HtmlResponse(url=spider.browser.current_url, body=spider.browser.page_source, encoding='utf-8', request=request)


class ZhihuSpiderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, dict or Item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Response, dict
        # or Item objects.
        pass

    def process_start_requests(self, start_requests, spider):
        # Called with the start requests of the spider, and works
        # similarly to the process_spider_output() method, except
        # that it doesn’t have a response associated.

        # Must return only requests (not items).
        for r in start_requests:
            yield r

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)


class ZhihuDownloaderMiddleware(object):
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info('Spider opened: %s' % spider.name)
